[Diagnosis and management of hereditary colorectal cancer according to the JSCCR Guidelines 2012 for the Clinical Practice of Hereditary Colorectal Cancer].

We summarized the key points of the diagnosis and management of familial adenomatous polyposis (FAP) and Lynch syndrome (LS) according to the JSCCR Guidelines 2012 for the Clinical Practice of Hereditary Colorectal Cancer. The diagnosis of FAP is made clinically and/or genetically. A total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the standard treatment for preventing the development of colorectal cancer, while a total colectomy with ileo-rectal anastomosis (IRA) is an alternative option in select patients. Surveillance for the remnant (colo) rectal mucosa and extra-colonic manifestations, such as the desmoid tumors or duodenal polyposis, is important. Meanwhile, genetic testing is essential for the diagnosis of LS. The genetic testing for mismatch repair gene (s) (MLH1, MSH2, MSH6, and PMS2) is performed using a microsatellite instability test or immunohistochemistry for the 4 kinds of mismatch repair proteins in colorectal cancer tissue from patients who meet the Amsterdam criteria or the revised Bethesda guidelines. Surveillance for metachronous colorectal cancer and extracolonic neoplasms is mandatory in LS patients undergoing surgery for initially diagnosed colorectal cancer.